Sol (1) 0

3xy-x = 3y

x(3y-1) =3y 

=> x = 3y/(3y-1)

=> x = (3y-1+1)/(3y-1)

=> x = 1+ 1 /(3y-1)

For x to be an integer 1/(3y-1) should be an integer value

Hence 3y-1 can only take 1 or -1

So y will be 2/3 or 0.

For natural number there is no acceptable value

Hence no solution